The present invention is directed to methods and systems process or convert videos signals between standardized forms. Specifically, the invention is directed to methods and systems which use a common hardware system or method to process various different video signal formats.
Video source devices, such as set top boxes, TVs, and DVD players, often provide video in one or more of several standardized video formats, such as VGA, RGB and YPbPr. These video signals are typically input into video display devices and video recording devices which need to process the signals to decode or convert the signals to a form that facilitates display or recording. Typically, these video display devices and recording devices include separate subsystems for processing each of the different video formats and converting or decoding the input signal into the internal format that is used by the device.
In many cases, these video display and video recording devices include multiple inputs, allowing consumers to route multiple video sources through a single device for ease of viewing. This practice is also common with digital video devices such as digital TVs. It is desirable for these video devices to be compatible with pre-existing analog video sources, such as VGA sources and YPbPr sources because devices employing these formats are commonplace.
Analog formats such as VGA, RGB and YPbPr should be handled differently by digital video device. Generally, a digital video device will convert analog input formats to a common digital video format, such as YCbCr. The methods used for conversion of analog video signals to a digital video format vary with the input format. For instance, VGA/RGB format allows the device creating the signal to choose a frequency within a range, whereas YPbPr format uses a fixed frequency for the video signal. A digital video device receiving VGA and YPbPr inputs should sample these signals at different frequencies and use different methods and components when digitizing the analog signals. VGA sampling is performed by VGA specific circuitry capable of sampling at a variable frequency obtained from the VGA signal, whereas YPbPr sampling is performed by YPbPr specific circuitry that uses a fixed sampling frequency, which can be customized for that sampling frequency.